The problem at SFO continues to be the very closely spaced runways that make the airport extremely sensitive to reductions in the number of aircraft it can handle. That "trigger" is their loss of the ability to conduct "visual" approaches, usually anything less than a 2,500' cloud ceiling and/or anything less than 5 miles visibility. When they lose visuals, SFO's arrival rate goes from 60 an hour to as low as 30 an hour. Imagine the sudden backlog of cars on a six-lane freeway if three lanes of capacity disappear suddenly. The obvious critical difference here is backed up airplanes can't go bumper-to-bumper (in the air), so the delays ensue. Airborne flights turn circles, awaiting their shot at the airport, and anything headed to SFO that's still at its takeoff airport awaits their turn--not unlike a metered freeway ramp.
One of the things airlines (all of them) do when airspace capacity at an airport is radically reduced is to start prioritizing the use of the slots it has available. If there are flights that are lightly-booked, those will get canceled to allow a full(er) flight to operate, and minimize the number of inconvenienced Customers.
The same 2,500'/5 mile conditions at OAK, SJC, or SMF have virtually no adverse effect on creating delays (and their predictable side effects) given the lower traffic counts compared to SFO, and the fact that they have greater distances between any parallel runways in use there.
If your travel plans can't tolerate risking a delay/cancellation, and anyone has non-stop service off OAK, SJC, or SMF to where you want to go, I'd suggest that.
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.